Turbulence generation and liquid breakup are being studied due to their relevance to dense combusting sprays found in propulsion systems. Turbulence generation is the main source of turbulence in dense sprays; it consists of drop wake disturbances embedded in a turbulent interwake region. Both regions are unusual compared to conventional fluid flows: the drop wakes are laminar-like turbulent wakes typical of intermediate Reynolds number wakes in turbulent environments; the turbulent interwake region consists of isotropic turbulence in the little-studied final decay period. Work already completed has resolved the properties of the turbulent interwake region and overall flow properties for monodisperse particle (drop) flows; current work is addressing these properties for more practical polydisperse particles (drops). Primary and secondary liquid breakup are important because they are the rate-controlling processes of dense sprays and fix initial conditions for dilute sprays. Past work has shown that liquid breakup should be treated as a rate process and has provided the temporal properties of secondary drop breakup at large liquid/gas density ratios based on experiments. Current work is considering drop deformation and breakup based on time-dependent numerical simulations, emphasizing conditions where liquid/gas density ratios are small and effects of liquid viscosity are large, which are important for practical applications but are difficult to consider using experiments.